1. Field of Invention
The invention relates to methods and apparatuses for manufacturing hard book cases and, in particular, to machines for tucking and folding book cases.
2. Discussion of Related Art
Cases for hard cover books are typically produced by printing a rectangular sheet of paper, cloth or leather, known as the cover material, and subsequently gluing the cover material to a pair of panels and a spine. The panels and spine (the rigid component) provide rigidity for the case, with one of the panels forming the front of the finished book and the second forming the back. The spine provides rigidity to the spine portion of the book. The spine and panels are typically made of chipboard or other stiff material. In some cases, the spine is of a more flexible material. A space is usually left between the spine and the panels so that the cover may be opened and closed in hinge-like fashion. Manufacturing techniques typically include a step of placing the panels and spine on a glued cover material and then folding the edges of the cover material up and onto the inside edges of the panels (and the ends of the spine). Together, the spine, panels, and cover material are known as a hard book cover assembly or a hard book case.
In an unfinished hard book case, the cover material is sized and placed to extend outwardly past the periphery of the spine and the panels to be later folded back over the edges of the spine and panels to produce an attractive cover. The overlapping edges of the cover material are glued on the inside of the panels and spine, and these edges are generally hidden later in the book making process when paper or other material is glued over the interior of the hard book cover in a manner that overlaps, and thus hides, the edge of the cover material from a reader.
There are two main types of corner folding used to make hard cover books. One type of corner fold is known as an “edition corner” (also cut corner, standard corner, tucked corner or square corner). The second type is known as a “library corner.”
For edition corners, the cover material is typically cut into a rectangular shape that is about 1½ inches larger in each of the X and Y dimension than the desired finished (open and flat) book cover (case) size. When the cover material is affixed to the rigid components of the hard book case (for example, 2 panels and 1 spine) there typically is a cover material overhang of about ¾ inch around the outer edges of the rigid components. To remove excess cover material, the corners of the cover material typically are trimmed prior to affixing the cover material to the panels and spine. By eliminating this corner material, multiple layers of bunched cover material do not develop at the corners of the finished hard book case.
Cover material is often cut in a stack so that multiple pieces can be cut simultaneously in preparation for a run of many copies of the same hard book case. This is typically performed at a cutting station separate from the hard book case making apparatus.
An identically sized triangular piece is cut from each of the four corners as the spine and panel will be placed square and centered on the cover material. Preferably, these cuts are made at a 45 degree angle to the longitudinal edges of the panels leaving an amount of cover material extending outwardly from each of the outer four corners (in a direction bisecting the 90 degree corner of the panel) of each panel a distance that will be equivalent to approximately 2 times the thickness of the panel material in the finished product.
After the corners have been cut and an adhesive has been applied to the cover material, the spine and panels are placed on the cover material with the outer edges of the panels in parallel with the adjacent (closest) outer edges of the cover material. Each edge can be longitudinally folded over the panel to produce an edition corner that has only a small area of glued, overlapping cover material on the inside surface of each panel at the corner.
For a library corner, the corner of the cover material is not cut off, but is instead folded back over the corner of the panel prior to folding back the longitudinal edges of the cover material. This results in an extra layer of cover material on the inside of the panel.
Due to the ease with which books and manuscripts can be printed using modern technologies, such as digital printing, a need has developed for hard cover book making machines that can produce small numbers (tens or hundreds, for example) of hard covers for authors and publishers desiring hard covers for their works. Furthermore, as digital printing becomes available in numerous outlets, including copy shops, work places, internet sites and even homes, there has developed a need for hard cover book making machines that can be operated in these areas. In addition to being inexpensive, it may be desired that the book cover making machines require as small an amount of space as possible, are easy to set up, and require minimal skill and training for operation. Space considerations may be of particular interest in those locations with higher real estate expense than traditional publishing companies.
While apparatuses exist that can quickly fold edges of cover material over the rigid panels it is much more difficult to provide tucked corners on short run machines that are designed to produce a variety of different sized cases.